The interim coach had a lot on his mind to help the team grow, probably while he was the second under Ten Hag management he was not given enough audience to bring his own tactical reasoning on how help the team, Ten Hag might have closed his ideas. Just after the sack, we can visibly see the better part of the team, played 4 games for the club and never lost any. The team should have given him more time, maybe till the end of the season and see what will become of him because i feel Ruud Van also had same thought and was disappointed on how fast they demanded for a new coach to take the job. The new coach looks at his pick to help the club, i hope they no longer move from being bad to worst, Amorim can actually help the club, first on the list is pushing them back to top of the EPL and at the end securing the Europa title.
ETH brough Ruud to the coaching staff because they shared the same tactical approach. Sure, Ruud had better relations with the team, and had his own experience at Man United (Which definitely counts for something.), but being a manager is a different role entirely. Not flaming Ruud, but his only current option (that's public) is to manage Coventry. Whereas Amorim was wanted by the biggest clubs in England throughout this year.
History shows that whenever United appoints an interim/new manager, they go through a honeymoon phase. For e.g., Carrick (After Ole's departure): 2W, 1D; Ole: 5W (I could be wrong, but I think ETH and van Gaal were the only managers to have poor debuts since SAF.). Imho, INEOS appointing a new manager is exactly what the club needed, United may as well written off the season if they held on to Ruud as interim. They've shown decisiveness and ruthlessness, something the club has lacked for a very very long time.